Ferromagnetism in the large-U Hubbard model

We study the Hubbard model on a hypercubic lattice with regard to the possibility of itinerant ferromagnetism. Dynamical mean-field theory is used to map the lattice model on an effective local problem, which is treated with the help of the noncrossing approximation. By investigating spin-dependent one-particle Green's functions and the magnetic susceptibility, a region with nonvanishing ferromagnetic polarization is found in the limit U-->infinity. The delta-T phase diagram as well as thermodynamic quantities are discussed. The dependence of the Curie temperature on the Coulomb interaction and the competition between ferromagnetism and antiferromagnetism are studied in the large-Ci Limit of the Hubbard model.